Radioactive source container



J. A. COMMINS RADIOACTIVE SOURCE CONTAINER March 20, 1962 2 Sheets-Sheet 1 Filed Dec. 31, 1958 7 3 E w M m w n 7 7 a 5 a 7 w m M v ATTORNEY March 20, 1962 J. A COMMINS 3,025,414

RADIOACTIVE SOURCE CONTAINER Filed Dec. 31, 1958 2 Sheets-Sheet 2 VENTOR.

JA ME COMM/NS 3,026,414 RADIOACTIVE SOURCE tIQNTAINER James A. Commins, Pennington, NJ., assignor to Curtrss-Wrrght Corporation, a corporation of Delaware Filed Dec. 31, I958, er. No. 784,349 3 Uaims. (Cl. 250-106) This invention relates to a new and improved method and apparatus for handling radioactive materials.

More particularly, this invention relates to a new and improved container for storing or shipping radioactive sources and a new and improved method utilizing this container for replacing the radioactive source in a radiographic apparatus with a different radioactive source.

When using radiographic cameras, such as the ones disclosed in United States Patent No. 2,750,517 to Baum and pending application No. 683,268 filed September 11, 1957, by Meray-Horvath, now Patent No. 2,965,761, it occasionally becomes necessary to replace the radioactive source, either because the radioactivity of the old source has decreased below the desired level due to time or because it is desired to use a different type of source material.

Previously, in order to replace the radioactive source, it has been necessary to have specialized source handling equipment or else to return the camera to an installation having such equipment. These two alternatives have not been satisfactory since radioactive source handling equipment is expensive to install and maintain. Furthermore, it usually requires valuable space and skilled personnel for proper operation. When the camera is shipped to an installation having such equipment for a change of source, the camera is of course unavailable for use.

Accordingly, it is an object of this invention to provide a new and improved container for easily and economically storing or shipping radioactive sources.

It is a further object of this invention to provide a method for replacing the radioactive source in a radio graphic camera without using expensive remote handling apparatus or personnel skilled in the handling of such apparatus.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIGURE 1 is a longitudinal sectional view of one embodiment of the container;

FIGURE 2 is a longitudinal sectional view of a second embodiment of the container;

FIGURE 3 is a sectional view taken along the line 33 of FIGURE 2; and

FIGURE 4 is an enlarged view of the central portion of FIGURE 2.

Referring to the drawings and more particularly to the embodiment shown in FIGURE 1, there is shown a container, indicated generally by numeral 12, comprising a block of shielding material 13, such as lead, contained within a housing 14, made of shielding material, such as steel or the like. The housing 14 has its external surface 15 in contact with the surrounding atmosphere.

Disposed within the shielding material 113, 14 are two passageways 16 and 18 which are configurated to contain nits tats ter 3,@26,4l4 Patented Mar. 20, 1962 respectively one of the radioactive sources 17 and 19 in a shielded position within the shielding material. To each exposed end of each passageway 16, 18 is respectively attached one of the fittings 21, 22 and 23 for connection with flexible tubing or closure plugs which are not illustrated in order to avoid unnecessarily complicating the drawing.

Normally, when received by the user of a radiographic camera from the installation supplying radioactive sources, there will be a new source 1.7 in the shielded position in passageway 16, passageway 18 will be empty, and fittings 21, and 22 will be plugged by plugs, not shown, having flexible cables extending into passageway 16 to keep source 17 from shifting during transit.

In operation, to replace the source in a radiographic camera, fitting 23 is connected to the flexible source transmitting tube of the camera and the source 19 from the camera is blown into the passageway 18 by gas pressure. The flexible source transmitting tube from the radiographic camera is then shifted to fitting 22 and a com-. pressed gas line is connected to fitting 21.

The plug and flexible cable, not shown, formerly attached to fitting 22 is now attached to fitting 23 to seal passageway 18. Compressed gas is then blown through fitting 21, passageway 16, fitting 22, and the flexible source transmitting tube of the radiographic camera; said compressed gas serving to blow source 17 into the radiographic camera body.

Referring next to the embodiment illustrated in FIG- URES 2, 3, and 4, there is shown in FIGURES 2 and 3 a container, indicated generally by numeral 32 and having an outer housing 36 made of shielding material such as wood or the like. Arranged substantially centrally within the housing 36 is a block of shielding material 33, such as lead, contained within a second housing 34, made of shielding material, such as steel or the like.

The housing 34 is maintained in spaced relationship from the housing 36 by means of supports 37, 38, 39, suitably attached.

Completing the outer housing '36 is a top housing plate 41, made of shielding material, such as steel or the like. The outer housing 36, 41 has an external surface 42 in contact with the surrounding atmosphere. A portion of the shielding material of the container is also formed by the gas space 43 between the housings 34 and 36.

Disposed within shielding material 33 and extending through gas space 43 and top housing plate 41 are two pairs of tubes 46, 48 and 47, 49 made of shielding material, such as brass, defining two passageways 44, 45. Since the two passageways may be identical, further description of the structure will be limited to a single passageway 44, it being understood that the same description will also apply to passageway 45. 1

The exposed end of tube 46 is provided with a female fitting 51 for connection with flexible compressed gas tubing, not shown, or a closure plug, not shown. The exposed end of tube 48 is provided with a male fitting 52 for connection with a flexible source transmitting tube, not shown, or a closure plug, not shown.

Passageway 44 is configurated to contain a radioactive source 53 in a shielded position. FIGURE 4 is an enlarged view of the zone of the container including the shielded position of passageway 44. Shielding material 33 has a hollow portion 56 adjacent the shielded portion of passageways 44, 45, which hollow portion connects with hollow portion 57 which extends through portion 33 and housing 34 to provide access to hollow portion 56 from the outside. Normally, hollow portion 57 is filled with plug 58, made of shielding material, such as lead, having a housing portion 59 adapted to be fastened securely to housing 34. Plug 58 has a small peripheral portion 61 cut away to leave a small passageway extending from hollow portion 56 to gas space 43.

As can best be seen in FIGURE 4, tubes 46 and 48 are joined in hollow space 56 to form a continuous passageway 44 and to position bafile disc 62 therein. Tube 48 has an enlarged diameter near its end to provide a shoulder 64 against which baffle disc 62 is seated and held by the insertion thereagainst of the end of tube 46.

Battle disc 62 contains openings 63 to allow passage of compressed gas Without permitting passage of radioactive source 53. The cushion of gas adjacent the face of battle disc 62 also serves to cushion the impact of .source 53 when the source 53 is blown into the container 32.

Also located within the hollow portion 56, is a switch 66 (see FIGURE 4) having a contact member 67 extending through opening 68 in the wall of tube 48. Contact member 67 is positioned to actuate switch 66 when radioactive source 53 is in its shielded position within passageway 44 in container 32. Attached to switch 66 are two conductors 70, 71 which pass through cut-out 61 and connect to an electric source (such as battery 73 shown in FIGURE 2) and indicator means (such as a light bulb 72) mounted on plate 41.

Container 32 will normally be fitted with a conventional cover, not shown, by hinges and clasps to complete the container and protect exposed elements 51, 52, 72, 73 during shipping or storage. Plugs, not shown, having flexible cables extending therefrom, will normally be inserted into fittings 51, 52 to prevent source 53 from shifting from its shielded position during movement of the container. If desired, a manually operated switch, not shown, may be inserted into the circuit including battery 73 and bulb 72.

In operation, to replace the radioactive source in a radiographic camera with a different radioactive source from container 32, the following procedure is used. The container 32 having a radioactive source in a shielded position of one of its passageways is transported to the location where the radiographic camera is being utilized. The cover, not shown, is opened and the plugs, not shown, are removed from fittings 51, 52 on each of the tubes 46, 47, 48, and 49. Source indicating means 72 is activated, as by closing auxiliary manually operated switches, not shown.

One passageway (for example, 44) contains a radioactive source in its shielded position as indicated by the bulb 72 and the other passageway (for example, 45) is empty. The flexible source transmitting tube of the radiographic camera is attached to fitting 52 of empty passageway 45 and the radioactive source 53 from the camera is blown into passageway 45 by gas pressure. When the source 53 from the camera arrives at its shielded position in passageway 45 against baflie 62, it activates switch 66 to indicate by means 72 its presence in a safe or shielded location.

The flexible source transmitting tube from the radiographic camera is then transferred to fitting 52 on tube 4.4 and a compressed gas tube is attached to fitting 51 on tube 44. The source 53 is then blown by compressed gas pressure from its shielded position in tube 44 through the flexible source transmitting tube and into the radiographic camera. As soon as source 53 leaves the shielded position of tube 44 separate indicating means 72 indicates its departure.

When replacement source 53 arrives at the radiographic camera, the tubes are removed from fittings 51, 52 and the plugs are reinserted, indicating means 72 is deactivated, and the cover is closed.

In this manner, a container is provided which is adapted to hold radioactive sources in shielded positions which may conveniently be stored or shipped and which is adapted to expedite the replacement of radioactive sources in radiographic cameras rapidly and with a minimum of expense. The radioactive sources may be cylindrical, spherical, or other shapes. The compressed gas may be air, nitrogen, or other inert gas.

While the invention has been illustrated and described as embodied in a radioactive source storage and shipping container, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A container for radioactive sources in which said radioactive sources are inserted and removed from said container by fluid pressure comprising, in combination, a housing having an external surface in contact with a surrounding medium; shielding material mounted within said housing, said shielding material having at least one passageway therein leading to the surface of said shielding material and communicating with the surrounding medium, said passageway having at least a portion thereof passing through a shielded position within said shielding material; switching means directly actuated by said radioactive source while in said shielded position for indicating the presence of said radioactive source in said shielded position and means to partially obstruct said passageway adapted to cushion the impact of said radioactive source and to position said radioactive source in said shielded position.

2. A container for radioactive sources comprising, in combination, a housing having an external surface in contact with a surrounding medium; shielding material mounted with said housing, said shielding material having at least one passageway therein leading to the surface of said shielding material and communicating with the surrounding medium, said passageway having at least a portion thereof passing through a shielded position within said shielding material; an electrical switch directly actuated by said radioactive source while in said shielded position; means to partially obstruct said passageway adapted to cushion the impact of said radioactive source and to position said radioactive source in said shielded position; and indicator means responsive to the actuation of said electrical switch for indicating the location of said source with respect to said shielded position.

3. A container for radioactive sources comprising, in combination, a housing having an external surface in contact with a surrounding medium; a solid block of shielding material mounted within said housing and spaced therefrom, said shielding material having at least one passageway having a gas therein leading to the surface of said shielding material and communicating with the surrounding medium through said housing, said passageway having at least a portion thereof passing through a shielded position within said shielding material; a perforated disc obstructing said passageway whereby the gas between said radioactive source and said perforated disc is compressed by said radioactive source in moving toward said perforated disc whereby the impact of said radioactive source in striking said perforated disc is cushioned, said perforated disc acting as a stop for positioning said radioactive source in said shielded position; and indicator means including an electrical switch directly actuated by said radioactive source for indicating the location of said source with respect to said shielded position.

References Cited in the file of this patent UNITED STATES PATENTS 6 Untermyer July 2, 1957 Ginns Apr. 1, 1958 Meilink Nov. 25, 1958 Forrer et a1 Mar. 3, 1959 Prest Dec. 8, 1959 OTHER REFERENCES International Conference on Peaceful Uses of Atomic Energy, Vol. 14, United Nations Press, pages 70 to 74,

Re. 24,544 Morganstein Sept. 30, 1958 2,514,909 Strickland July 11, 1950 2,750,517 Baum June 12, 1956 0 1955. 

1. A CONTAINER FOR RADIOACTIVE SOURCES IN WHICH SAID RADIOACTIVE SOURCES ARE INSERTED AND REMOVED FROM SAID CONTAINER BY FLUID PRESSURE COMPRISING, IN COMBINATION A HOUSING HAVING AN EXTERNAL SURFACE IN CONTACT WITH A SURROUNDING MEDIUM; SHIELDING MATERIAL MOUNTED WITHIN SAID HOUSING, SAID SHIELDING MATERIAL HAVING AT LEAST ONE PASSAGEWAY THEREIN LEADING TO THE SURFACE OF SAID SHIELDING MATERIAL AND COMMUNICATING WITHTHE SURROUNDING MEDIUM, SAID PASSAGEWAY HAVING AT LEAST A PORTION THEREOF PASSING THROUGH A SHIELDED POSITION WITHIN SAID SHIELDING MATERIAL; SWITCHING MEANS DIRECTLY ACTUATED BY SAID RADIO ACTIVE SORUCE WHILE IN SAID SHIELDED POSITION FOR INDICATING THE PRESENCE OF SAID RADIOACTIVE SOURCE IN SAID SHIELDED POSITION AND MEANS TO PARTIALLY OBSTRUCT SAID PASSAGEWAY ADAPTED TO CUSHION THE IMPACT OF SAID RADIOACTIVE SORUCE AND TO POSITION SAID RADIOACTIVE SOURCE IN SAID SHIELDED POSITON. 